165 replies to this topic

[y2kvfr]

All you guys are driving up the fleabay shocks on me!

I should have rebid on one that went for $10.50, but the CFO is watching me

[CitizenOfDreams]

I just thought of something... The rear shock does not sit vertical. So if you measure the VFR shock, then measure the CBR shock, then add the difference to the _bracket_ rather than the _shock_ itself... your suspension geometry (namely, riding height) will be quite different from original.
Anybody got measurements and/or AutoCAD drawings of 4th gen rear suspension? Or do you just "add shims till it feels right"?

[JamieDaugherty]

So... I decided to follow the trend and replace the rear shock on my 4th gen VFR with a newer CBR929 part. Here are the measurements I got:
- 4th gen VFR shock, eye center to eye center fully extended - 324mm
- CBR929 (yellow spring) shock, eye center to eye center fully extended - 288mm (36mm shorter)
- 4th gen VFR shock bracket, eye center to top surface - 25mm
- New bracket to be made, eye center to top surface - 61mm
Any corrections and suggestions would be greatly appreciated.

The VFR shock should be 325mm and the CBR929 one is 287mm for a difference of 38mm. That would make your bracket 63mm long. I'd even err to the side of more ride height and make thet bracket at least 65mm, maybe even longer.

[CitizenOfDreams]

Progress report... I bought a replacement bolt (100mm, which is 30mm longer than stock) and made the aluminum spacer (see the drawing below; unfortunately, it does not look as good in flesh - made with a hacksaw and a file instead of a milling machine). The 929 shock seems to fit, I will probably try to put it all together tomorrow.

[CitizenOfDreams]

The VFR shock should be 325mm and the CBR929 one is 287mm for a difference of 38mm.

My actual measurements were 324mm and 288mm... and it's too late now, the spacer is already made (yes, I've decided to go the easy route and make a spacer instead of a bracket). http://www.vfrdiscus...tyle_emoticons/default/smile.gif We shall see what it did to the riding height when I put it back together.

[JamieDaugherty]

More ride height helps on these bikes. I usually suggest at least 5mm but you can run up to 10mm if desired. It's about a 3:1 ratio of shock length to ride height. That means an increase of 5mm at the shock translates to 15mm at the axle.

[CitizenOfDreams]

More ride height helps on these bikes. I usually suggest at least 5mm but you can run up to 10mm if desired.

Thanks for the advice, I will make a taller adapter if I'm not happy with this one. Or maybe I should make them for sale in various sizes. http://www.vfrdiscus...tyle_emoticons/default/smile.gif

[thereisnospoon]

erion_1_resize.JPG


erion_2_resize.JPG
Got to invest a little bit of my thumb on the spring...


Here is my install. I used a <gasp> 3/8" grade 8, 5" </gasp> bolt because there weren't any 110MM 10MM bolts and I didn't feel like a goose chase. I used a ground down steel spacer with washers at each end for the additional needed length. It's a tad long but didn't take much to get in. I have the compression/rebound adjusters at about a third from full soft and I guessed at the sag and am two clicks towards stiff on the spring collar. Interested to see how it does.

[CitizenOfDreams]

Another progress report...
The new shock is in place. The battery box was a pain to reinstall. The ignition coils did not fit (the oil reservoir occupies a part of their private space) and had to be relocated. I was going to take pictures, but I lost my camera somewhere. Oh well...

[JamieDaugherty]

Another progress report...
The new shock is in place. The battery box was a pain to reinstall. The ignition coils did not fit (the oil reservoir occupies a part of their private space) and had to be relocated. I was going to take pictures, but I lost my camera somewhere. Oh well...

Are you sure that you have a 929 shock and not a 954 one? They are often mislabeled on eBay or labeled as fitting both (they don't). They only battery box interference problems I've seen have been with a 954 shock, the 929 should fit without any problems.